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<title>Compound Lvalues (GNU Compiler Collection (GCC) Internals)</title>

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<h4 class="subsection" id="Compound-Lvalues-1"><span>12.6.2 Compound Lvalues<a class="copiable-link" href="#Compound-Lvalues-1"> &para;</a></span></h4>
<a class="index-entry-id" id="index-Compound-Lvalues"></a>

<p>Currently compound lvalues involving array and structure field references
are not broken down; an expression like <code class="code">a.b[2] = 42</code> is not reduced
any further (though complex array subscripts are).  This restriction is a
workaround for limitations in later optimizers; if we were to convert this
to
</p>
<div class="example smallexample">
<pre class="example-preformatted">T1 = &amp;a.b;
T1[2] = 42;
</pre></div>

<p>alias analysis would not remember that the reference to <code class="code">T1[2]</code> came
by way of <code class="code">a.b</code>, so it would think that the assignment could alias
another member of <code class="code">a</code>; this broke <code class="code">struct-alias-1.c</code>.  Future
optimizer improvements may make this limitation unnecessary.
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